macOS over Ubuntu (don't get me started on Windows). I use macOS on my MacBook Air and it's just so well thought out. Ubuntu is decent but I wouldn't want to use it for my daily work.
I love Obsidian and use it to manage my Markdown files and I'm in awe. Checked out Logseq as well but it didn't work for me.
VS Code. As much as I hate Microsoft, this is great. I'll likely look for a community-supported version without the creepy telemetry shit though.
Dead Internet Theory is a thing.